U.S. reports say rising sea levels threaten infrastructure

By Cornelia Dean

A rise in sea levels and other changes fueled by global warming threaten roads, rail lines, ports, airports and other important infrastructure in the United States, according to new U.S. government reports, and policy makers and planners should be acting now to avoid or mitigate their effects.

While increased heat and "intense precipitation events" threaten these structures, the greatest and most immediate potential impact is coastal flooding, according to one of the reports, by an expert panel convened by the National Research Council, the research arm of the National Academy of Sciences.

Another study, a multi-agency effort led by the Environmental Protection Agency, sounds a similar warning on coastal infrastructure but adds that natural features like beaches, wetlands and fresh-water supplies are also threatened by encroaching salt water.

The reports are not the first to point out that rising seas, inevitable in a warming world, are a major threat. For example, in a report last September, the Miami-Dade County Climate Change Task Force noted that a rise of two feet, or a little over half a meter, by the year 2100 as predicted by the United Nations' Intergovernmental Panel on Climate Change "would make life in South Florida very difficult for everyone."

But the new reports offer detailed assessments of vulnerability in the relatively near term. Both note that coastal areas are densely populated, economically important and gaining people and investment by the day, even as scientific knowledge of the risks they face increases. Use of this knowledge by policy makers and planners is "inadequate," the academy panel said.

"It's time for the transportation people to put these things into their thought processes," Henry Schwartz Jr., the chairman of the research council panel, said in an interview.

The 218-page academy report, "Potential Impacts of Climate Change on U.S. Transportation," was issued Tuesday and is available at www.nationalacademies.org.

Noting that 60,000 miles, or 100,000 kilometers, of coastal highways are already subject to periodic flooding, the academy panel called for policy makers to survey vulnerable areas - "roads, bridges, marine, air, pipelines, everything," Schwartz said - and begin work now on plans to protect, reinforce, move or replace on safer ground. Those tasks will take years or decades and tens of billions of dollars, at least, he said.

"We need to think about it now," said Schwartz, a member of the National Academy of Engineering.

The multi-agency report, a draft assessment, is one of a series intended to help policy makers do just that. The 800-page draft, "Coastal Sensitivity to Sea Level Rise: A Focus on the Mid-Atlantic Region," was posted last month for public review at www.climatescience.gov/Library/sap/sap4-1/public-review-draft/. It focuses on the area from Montauk Point on Long Island, New York, to Cape Lookout, North Carolina.

Produced by a collaboration among agencies including the U.S. Geological Survey, the National Oceanographic and Atmospheric Administration and the Department of Transportation, the report offers three estimates for sea-level rise by 2100: about 16 inches, or 40 centimeters, a century, a rate it said has already been exceeded; about 2 feet, an estimate many scientists regard as optimistic; and up to 3 feet, which the report says would be catastrophic for wetlands and other coastal features but is "less than high estimates suggested by more recent publications." The academy report cited similar estimates.

The multi-agency report cited as an example the Port of Wilmington in Delaware. The report says that if the sea level rises by two feet or even a bit less, 70 percent of port property will be affected.

Meanwhile, it says, such a rise in sea level would leave almost 2,200 miles of major roads and almost 900 miles of rail lines in Maryland, Virginia, North Carolina and the District of Columbia "at risk for regular inundation."

The academy report made similar points, noting, for example, that airports in many large coastal cities are built in tidal areas, often on fill, placing them at greatest risk. In metropolitan New York, Newark and LaGuardia are particularly vulnerable, Schwartz said.

To be continue in other article...

(Jakarta, Rabu 19 Maret 2008)

Re-publish by Jacob Paradox from link (www.routers.com),(www.iht.com), (www.routers.com), (www.nytimes.com)